onLeave with a TextFormField - Flutter/Dart

Question

I am using an onChange method in a TextFormField widget... but is there a onLeave function on another parent widget.... I looked into GestureDetector but they also don't have it

TextFormField(
     controller: _emailAddress_controller,
     keyboardType: TextInputType.emailAddress,
     validator: validateEmail,
     onChanged: (value) {  
        print(validateEmail(_emailAddress_controller.toString()));
      },
)

Answer 1

We don't have onLeave() but we surely do have onFieldSubmitted() for TextFormField(). It triggers some code when the user presses submit on the right-hand corner of the keyboard.

I'm assuming you want to move the focus on to a different textfield when the user leaves first textfield so you can use FocusNodes.

FocusNode _secondFieldFocusNode = FocusNode(); //declaration



//on the first field's onFieldSubmitted Fn, let's put some code.
TextFormField(
 onFieldSubmitted: (value) {
  FocusScope.of(context).requestFocus(_secondFieldFocusNode),
 ),

//assign the focus node to second field
TextFormField(
 focusNode: _secondFieldFocusNode,
)